The Five Power Defence Arrangements (FPDA) are a defence relationship established by an agreement between the United Kingdom, Australia, New Zealand, Malaysia and Singapore signed in 1971, whereby the five nations will consult each other in the event of external aggression or threat of attack against Malaysia or Singapore. The FPDA was set up following the termination of Britain's defence guarantees of Malaysia and Singapore as a result of Britain's decision in 1967 to withdraw its forces east of Suez.

The FPDA provides for defence co-operation, and for an Integrated Air Defence System (IADS) for Malaysia and Singapore based in RMAF Butterworth under the command of an Australian (2-star) Air Vice Marshal. RMAF Butterworth, until 1988 under the control of the Royal Australian Air Force, is now owned by the Royal Malaysian Air Force, but hosts rotating detachments of aircraft and personnel from all five countries.

In 1981, the five powers organised the first annual land and naval exercises. Since 1997, the naval and air exercises have been combined.

In 2001, HQ IADS was redesignated Headquarters Integrated "Area" Defence System. It now has personnel from all three branches of the armed services, and co-ordinates the annual five-power naval and air exercises, while moving towards the fuller integration of land elements.